REXEC(3)                                            Linux Programmer's Manual                                           REXEC(3)



NAME
       rexec - return stream to a remote command

SYNOPSIS
       int rexec(char **ahost, int inport, char *user,
                 char *passwd, char *cmd, int *fd2p);

DESCRIPTION
       This interface is obsoleted by rcmd(3).

       The rexec() function looks up the host *ahost using gethostbyname(3), returning -1 if the host does not exist.  Otherwise
       *ahost is set to the standard name of the host.  If a username and password are both specified, then these  are  used  to
       authenticate  to  the  foreign  host; otherwise the environment and then the user's .netrc file in his home directory are
       searched for appropriate information.  If all this fails, the user is prompted for the information.

       The port inport specifies which well-known DARPA Internet port to use for the connection; the call  getservbyname("exec",
       "tcp")  (see getservent(3)) will return a pointer to a structure that contains the necessary port.  The protocol for con-
       nection is described in detail in rexecd(8).

       If the connection succeeds, a socket in the Internet domain of type SOCK_STREAM is returned to the caller, and  given  to
       the  remote command as stdin and stdout.  If fd2p is nonzero, then an auxiliary channel to a control process will be set-
       up, and a descriptor for it will be placed in *fd2p.  The control process will return diagnostic output from the  command
       (unit 2) on this channel, and will also accept bytes on this channel as being Unix signal numbers, to be forwarded to the
       process group of the command.  The diagnostic information returned does not include remote authorization failure, as  the
       secondary  connection  is  set  up  after  authorization has been verified.  If fd2p is 0, then the stderr (unit 2 of the
       remote command) will be made the same as the stdout and no provision is made for sending arbitrary signals to the  remote
       process, although you may be able to get its attention by using out-of-band data.

CONFORMING TO
       Not in POSIX.1-2001.  Present on the BSDs, Solaris, and many other systems.  The rexec() function appeared in 4.2BSD.

BUGS
       The rexec() function sends the unencrypted password across the network.

       The  underlying  service  is  considered  a  big security hole and therefore not enabled on many sites, see rexecd(8) for
       explanations.

SEE ALSO
       rcmd(3), rexecd(8)

COLOPHON
       This page is part of release 3.25 of the Linux man-pages project.  A description of the project,  and  information  about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



Linux                                                      2007-12-28                                                   REXEC(3)